Delayed action hydrostatic switch



United States Patent 3,441,6596 DELAYED ACTIQN HYDROSTATEC SWITCH AxelL. Nielsen, 1316 E. Elza, Hazel Park, Mich. 48030 Filed Aug. 28, 1967,Ser. No. 663,718 Int. Cl. Htllh 35/24 U.S. Cl. 200-81 5 Claims ABSTRACTOF THE DISCLOSURE A delayed action hydrostatic switch is disclosed whichprovides for the rapid force draining of a receptacle, such as anaccumulating sump, a basement floor riser, a laundry tray or tub, andthe like, by a motorized pump. The switch is disciplined or controlledto delay its deenergization and that of the pump motor, once pumping hascommenced, until the receptacle is substantially dry. Thus, water isdrained by the pump from the receptacle in a very fast way, indeed.

The result is brought about by maintaining within the receptacle acolumn of liquid distinct from the liquid being directly pumped from thereceptacle. This liquid column surrounds the lower end of an uprightpressure transmitting tube and traps therein a column of air acting on aflexible diaphragm of the switch. The upper end of the outer tube, intowhich the liquid initially enters in substantial volume and at aflooding rate from the main liquid body in the receptacle, is at anelevation no less than that at which the liquid Within the inner tubewill sufliciently drop the compression of the trapped air column topermit opening of the motor switch and terminate pumping. Actually, andas disclosed herein, the upper end of the outer tube will be well abovethis level, in the interest of securing a more extended period ofpumping.

An essential feature resides in the fact that the outer tube has valveor equivalent restriction means, as at its lower portion, to insure thatthe columns of liquid in it and in the inner tube will drain therefrommuch more slowly than the dropping of liquid level in the remainder ofthe receptacle by pumping. This is to such an extent, preferably, thatthe sump, riser, tub, tray, or other receptacle will normally be whollyemptied before the level in the inner tube has dropped enough to lowerthe hydrostatic-pressure on the switch diaphragm and stop the pump. Thecycle repeats after both tubes have drained empty and the liquid levelin the main receptacle has risen sufiiciently to raisehydrostatic-pressure on the switch diaphragm to start the pump again.

A simple adjustment of the valve or like drain control restriction ofthe outer tube permits a reliable regulation of the rate of draining ofthe outer tube, for a tube of any given inner diameter and height.

Background 0 the invention Difliculties have heretofore been experiencedin the force-pumping of basement flood or seepage accumulator sumps andfloor risers, also laundry tubs, and the like, in which initiation andtermination of the operation of the pump motor is under control of apressure responsive switch, usually of the diaphragm type. Briefly, ithas been found that as time goes on the commencement and duration ofpumping lack uniformity in succeeding pumping cycles, with the resultthat many customer complaints have been received.

The present invention provides a method of rapidly force-draining areceptacle, employing a delayed action, hydrostatic pressure-responsive,diaphragm type switch 3,441,696 Patented Apr. 29, 1969 whose controlprovisions reliably and accurately time the uniform commencement andtermination of pumping, hence eliminate the cause of complaint.Furthermore, they insure a very rapid and complete emptying of thereceptacle.

Gross reference to related application The improvement is related in ageneral way to that of my copending application, Ser. No. 371,293, filedJune 1, 1964, now abandoned and entitled Drainage Accumulator andPumping System.

In my U.S. Patent No. 2,922,854, Jan. 26, 1960, I have disclosed a sumppump control which utilizes a control means to alter the rate ofvertical rise of liquid entering a tube, such as the tube 70 hereof. Thepresent invention may be incorporated into such structure, if desired.

Summary of the invention The invention relates to a method and equipmentfor repeatedly draining a receptacle of liquid with great rapidity andin pumping cycles of uniform duration. A hydrostatistically responsivepump control switch housing is variably pressurized in a pressurechamber thereof through a first upright tube, thus to actuate a pumpmotor control switch as the tube is increasingly pressurized. Thisoccurs when the liquid level in the receptacle rises predeterminedly.However, the deactuation of the switch is caused to be substantiallydelayed notwithstanding a drop in the receptacle level under pumping, infact until the receptacle is wholly pumped out.

This result is bad by providing a second tube of larger diametersurrounding the first tube and filled from above with liquid at apredetermined receptacle level. The second tube has a restricted gravitydischarge at its bottom, and thus maintains a head of water about and inthe lower end of the first tube. The restricted discharge then occasionsa much slower drop of head in the tubes than the drop of the level inthe receptacle being pumped; and this in turn produces the desiredincrease in time of the pumping operation.

Brief description of the drawing FIGURE 1 is a side elevational andvertical sectional view of the delayed action hydrostatic switch asmounted on tub type of receptacle;

FIGURE 2 is a top plan view of the switch; and

FIGURE 3 is a schematic view of the electrical system employed with theswitch.

Description of a preferred embodiment Referring to the drawing, it willbe noted that the delayed action hydrostatic switch 10 is mounted to alaundry tub or like receptacle 12. However, it is to be understood thatthe switch is equally applicable in the force draining of a sump, aflood or seepage accumulating floor riser (as in my copendingapplication identified above), etc. The receptacle 12 is provided withan outlet or basket 14 in its bottom wall 16; and a centrifugal pump 18,illustrated diagrammatically, is connected to the outlet for rapidlydraining the tub to a sewer or other main drain under a pressure headgreater than that provided by gravity.

The hydrostatic switch 10 includes a U-shaped support member 20 whichserves to carry the working components of the switch structure and tosecure the structure to the receptacle 12. As will be noted, the upperedge portion of the tub side wall 22 is received within the cavitydefined by the support 20; and a clamping screw 24 is threadedlyreceived in an opening provided in the outer wall 26 of the support 20.The screw 24 engages the outer surface of the side wall of the tub and,with the end wall 28 3 of the support 20, causes the switch structure tobe firmly secured to the tub.

A diaphragm and switch housing 30, which is of known type comprisingupper and lower halves 32, 34 is secured to the support 20 by means ofscrews 36. A flexible diaphragm 38 extends across the interior of thehousing and divides the housing into an upper switch receiving portion.The diaphragm 38 is secured between the housing halves by meansincluding an annular gasket 42, to make the housing fluid-tight, andscrews 44.

The upper housing half 32 is provided with a central internally threadedboss 46 which threadingly receives an externally threaded tubularportion 48 of a normally open pressure sensitive electrical switch 50;and an electrical cable 52 leads from the switch 50 to a power source,as will more fully be described in connection with the electricaldiagram illustrated in FIGURE 3. The switch 50 has a downwardlydepending actuating element 54 which serves to open and close theswitch, the element 54 being shown in a position to cause the switch tobe open. It downwardly contacts a pad 56 on the upper surface of thediaphragm 38. Upward movement of the diaphragm will, at a predeterminedpressure therebelow, cause the element 54 to be depressed to close theswitch and energize the motor which drives pump 18.

The switch 50 is of a conventional type in that it takes a pressure of,for example, eight ounces, to depress element 54 and close the switch.The element 54 will not return to its initial position until thepressure has been reduced to a lower value, as for example four ounces.

A female electrical connector 58 is mounted on the upper housing 32; andthis connector is adapted to receive a male connector (not shown)through which the motor of pump 18 is energized. Another cable 60 leadsfrom female connector 58 to the switch 50. A manual offon overrideswitch 62 is also mounted on the housing, with an operating element 64thereof being externally accessible for arbitrarily turning the pump 011and on by overriding switch 50.

The lower housing portion 34 has a central internally threaded boss 68;and an elongated tube 70 having a threaded portion 72 on the upper endthereof is received in the bore 68. The tube 70 extends downwardlytowards the bottom of the receptacle 12, terminating a short distancefrom the latters bottom surface. A fitting member 74 is threadedlyconnected into the housing boss 68 and secured to the top of tube 70 tomake a union in this zone.

An outer tubular drainage control member 76 surrounds the lower portionof the tube 70, the upper portion of the outer tube 76 may be closed bya screen 78 which perrnits free, in fact a flooding, overflow passage ofliquid into the top of outer tube 76 at a predetermined liquid level inreceptacle 12, but filters solid materials.

The inner, pressure transmitting tube 70 terminates at a point short ofthe lower end of the control tube 76 and perforated spacer 80 isprovided at the lower end of the tube 70 to secure the latter in theproper position and to provide support for the outer tube 76, at thesame time keeping the two tubes in free communication with one anotherat the bottom of the innermost.

An annular resilient plug member 82 is inserted in the outer tube 76 atthe lower end thereof, which plug member 82 may be removable to permitcleaning of the unit. In any event, it has a central aperture 84, orsome equivalent means, which serves as a restriction to thegravitational flow of liquid out of the outer tube 76, hence also out ofthe tube 70. This essentially is the basis of the delayed drainagecontemplated by the inventor. Typically, for the purpose a closureelement 86 is provided on the undersurface of the plug 82, being securedby means of a nut and bolt device.

Thus the closure member may be pivoted about the axis of the nut andbolt structure to partially cover or fully expose the aperture, so thata variable restriction to the flow of liquid from the outer tube isprovided. This enables an adjustment of the duration of the force drainoperation.

The electrical circuitry of the system is illustrated in FIGURE 3. Threeleads, namely positive lead 92, ground lead 94 and negative lead '96extend from a source of power. The ground and negative leads 94, 96 aredirectly connected to pump 18. The positive lead 92 is connected to aterminal 98 of the pressure sensitive switch 50. A lead 100 extends fromthe other terminal 102 and is connected to a terminal 104 of the manualoverride switch 62. A lead 106 extends from the terminal 98 of switch 50and is connected to a terminal 108 of the switch 62. A lead 110 extendsfrom the terminal 104 to the pump 18.

As will be appreciated from the above-described circuit, the switches50, 62 are arranged in parallel. Closure of either switch will thuscause the pump 18 to be activated. When the switch 50 is closed by thediaphragm 38, the pump will begin operation. A similar result may beachieved by manual closure of the switch 62.

In the operation of the improved switch and system, reference being hadto FIG. 1, a rise of liquid in the receptacle 12 will eventually fioodthe outer tube 76 from above; and it will be assumed that when thecolumns of liquid therein and in the inner tube 70 rise to a 'heightindicated, for example, at 90 the air trapped in the tube '70 becomessufficiently pressurized to operate diaphragm 38 and close the normallyopen switch 50, thus causing the motorized drive of pump 18. A rapidforced evacuation of receptacle 12 ensues, but the drop of level intubes 70 and 76 proceeds much more slowly, until it reaches a level,say, at 112 at which the air column in tube 70' is sufficientlydecompressed to permit switch 50 to open.

By this time, receptacle 12 will have been completely drained, and therestriction valve 86 may be adjusted so as to delay pumping still more,if desired. At any rate, the tubes 70 and 76 continue to draingravitationally, until the lower end of the pressure transmitting tube70 is wholly exposed, whereupon it refills with air preparatory to thenext tub pumping cycle.

While the outer control tube 76 is shown as being of a quite extendedheight, for a considerably protracted pumping period, it will beunderstood that, pursuant to the principle of the invention, the outertube need be of a height only to exceed the critical lower level, forexample at 112, at which diaphragm 38 is depressurized and pumpingterminates.

What I claim as my invention is:

1. A delayed action hydrostatic switch comprising a housing providing ahydrostatic pressure chamber, a first open-ended tubular member incommunication with said chamber and extending from said housing fordisposition in a receptacle from which liquid is to be drained, saidchamber being variably pressurized in accordance with the level ofliquid in said tubular member, and a second tubular member surroundingat least the lower portion of the first member and adapted to receiveliquid from said receptacle at a predetermined liquid level in thelatter, there being a liquid flow restriction in at least one of saidtubular members acting to delay draining thereof during draining of thereceptacle.

2. The switch of claim 1, in which the upper portion of the secondtubular member is exposed to liquid in the receptacle to permit rapidfilling of said second member when the liquid level in the receptaclerises predeterminedly, and further comprising a pump connected to thereceptacle to drain the latter, and pump-controlling switch means on thehousing operated in response to pressurization of said chamber by arising level of liquid in the first tubular member to operate the switchmeans and actuate the pump, a relatively slowly falling level of liquidin the second tubular member reducing the pressure in said first memberand chamber to a predetermined point to deactuate the pump in delayedtime relation to the draining of the receptacle.

3. The device of claim 1, in which said liquid flow restriction isadjustable.

5 4. The device of claim 1, in which said liquid flow restriction is onsaid second tubular member.

5. The device of claim 2, in which said liquid flow restriction is onsaid second tubular member and is adjustable in 'area.

References Cited UNITED STATES PATENTS 2,514,632 7/1950 Flubacker200-8391 XR 3,043,225 7/1962 Nielsen ZOO-83.91 XR 3,055,994 9/1962Lundeen 20083.91 XR 6 3,250,872 5/1966 Hellman 20083.1 3,363,075 1/1968Jordan et a1. ZOO-83.1 3,200,389 8/1965 Damico et a1. 200-81 XR 5 ROBERTK. SCHAEFER, Primary Examiner.

H. BURKS, Assistant Examiner.

US. Cl. X.R.

